Personally, I believe that if Westerns are only about location or topography they are a very thing and fragile genre. I don't know of any other genre that isn't about the ideas contained or discussed in it. Location isn't an idea.

Westerns are often about the "Passing of the Frontier." Possibly this is why they mostly take place at the END of the era rather than its beginning. This would include the concepts of the coming of civilization (a retelling of the American Colonial experience at the last moment in history when it was slightly similar to the original).

It often has to do with the differences between one generation from another (a hard, almost immoral, generation of founders being criticized by a younger, more civilized crowd).

It also has a fundamental that shows up fairly often that my old mentor (film director) Alexander MacKendrick called "a love story between men." Two strong, opinionated guys, often with VERY different outlooks, often of different generations (see above), come to appreciate and respect one another. Occasionally, this is even played between men and women (Hondo, maybe) in romantic circumstances. This is also where you get some interesting variations like Brokeback Mountain because it takes the "love story between men" trope and makes it literal.

I have always felt that there were great similarities between Louis's Yondering stories and his Westerns. Yondering is about the passing of a different kind of frontier, a world that was big enough and wide enough to not be completely regulated even though there were huge colonial powers (England, Holland, Japan, France) that were trying to lock it down. It took not only governments to close the freedom of the world off, it took the sort of technology that finally appeared because of WWII, communications and data processing and storage. Today we may be seeing an even greater closing of the "frontier." I wonder if the world will open up again for a long time, this is not just because of Covid but because many governments around the world are in transition. Not just the US but Europe and many other places.

It is possible that you could just as easily tell a adventure story set in the modern world about two strong yet differing personalities being forced to learn to respect one another while dealing with the generational differences of old and young and give it all the qualities of a classic western.